Farnesene-based polymers and liquid optically clear adhesive compositions incorporating the same

Abstract

A low viscosity polymer having a linear or branched backbone derived from farnesene monomers and at least one terminal-end functionalized with a hydroxyl group. This polymer may be further hydrogenated to reduce unsaturation and acrylated, such that it may be incorporated into a LOCA composition. The LOCA composition may be used in a laminated screen assembly, such as a touch screen, for electronic devices by adhering the LOCA composition between an optically transparent layer, such as a cover glass, and a display. The cured LOCA composition has a refractive index similar to the optically transparent layer. A method of making the low viscosity polymer for the LOCA composition includes anionically polymerizing farnesene monomers, quenching a living end of the polymer to provide the hydroxyl-terminated polymer; hydrogenating the hydroxyl-terminated polymer; and reacting the at least partially saturated hydroxyl-terminated polymer with at least one reagent to provide an acrylate terminated hydrogenated polymer.

We claim: 
     
       1. A laminated screen assembly comprising a transparent layer adhered to a display and a cured adhesive between the transparent layer and the display, wherein the cured adhesive is obtained by curing a liquid optically clear adhesive composition comprising a polymer derived from monomers comprising farnesene, the polymer being obtained from a diol prepared by anionically polymerizing monomers comprising farnesene to provide an intermediate polymer having two living ends, quenching the two living ends by reacting the two living ends with an alkylene oxide and a protic source, and hydrogenating the diol, wherein hydroxyl groups of the diol have been further reacted to provide terminal ends functionalized with (meth)acrylate groups and wherein the polymer has a degree of unsaturation less than or equal to 50%. 
     
     
       2. The laminated screen assembly of  claim 1  further comprising a touch panel sensor layer between the transparent layer and the display, wherein the cured adhesive is adhered to the touch panel sensor layer and one of the transparent layer and the display. 
     
     
       3. The laminated screen assembly of  claim 1 , wherein the cured adhesive has a refractive index within 10% of the refractive index of the transparent layer. 
     
     
       4. The laminated screen assembly of  claim 1 , wherein the cured adhesive has a refractive index within 5% of the refractive index of the transparent layer. 
     
     
       5. A polymer comprising a linear or branched backbone derived from monomers comprising farnesene, the polymer being obtained from a diol prepared by anionically polymerizing monomers comprising farnesene to provide an intermediate polymer having two living ends, quenching the two living ends by reacting the two living ends with an alkylene oxide and a protic source, and hydrogenating the diol, wherein hydroxyl groups of the diol have been further reacted to provide terminal ends functionalized with (meth)acrylate groups. 
     
     
       6. The polymer of  claim 5  having a degree of unsaturation less than or equal to 50%. 
     
     
       7. The polymer of  claim 5 , wherein hydroxyl groups of the diol have been further reacted with an acrylic anhydride, acrylic chloride, or a combination of a diisocyanate and an acrylate and hydroxyl group-containing compound to provide the terminal ends functionalized with the (meth)acrylate groups.